Referring to a connector which engages a flexible engagement piece with a terminal fitting and causes a terminal accommodation chamber to hold the same therein, a rigidity of the flexible engagement piece is lowered due to a reduction in a size. For this reason, there is a fear that a reliability of a function for preventing a slip-off of the terminal fitting might be deteriorated. For example, Patent Document 1 discloses a connector which tries to solve the problem. In a connector shown in FIGS. 7(a) and 7(b), a front end side of a flexible engagement piece (which will also be referred to as a “lance”) 501 is set to be an equal width portion 503 having a small width and a residual portion is set to be a taper portion 505 having a width increased gradually toward a base end. A reinforcing bead 507 is formed on a central part in a transverse direction over a lower surface of the lance 501, that is, an opposed surface to a flexure space.
The reinforcing bead 507 has an almost equal width to that of the equal width portion 503 of the lance 501 and has a starting end set to be a position recessed slightly backward from a starting end position of the taper portion 505 of the lance 501, and is formed with a backward extension over an external surface of a lower surface wall 511 of a cavity 509 forming a terminal accommodation chamber from the lance 501. A base end side to be a flexure supporting point of the lance 501 is set to be wide, and furthermore, the reinforcing bead 507 can also be set to be wide. Consequently, it is possible to obtain a high rigidity. Thus, it is possible to obtain a great elastic force, thereby enhancing the reliability of the function for preventing the slip-off of the terminal. Moreover, the width of the reinforcing bead 507 can be varied within a wide range so that the rigidity of the lance 501 can be regulated within a wide range.